Fuel injection system



Jan. 14, 1936. c. R. ALDEN 2,027,360

FUEL INJECTION SYSTEM Fild March 19, 1930 7 Sheets-Sheet 1 [722/67t7 par- 1; 51424271;

Jan. 14, 1936. c, R ALDEN 2,027,360

FUEL INJECTION SYSTEM Filed March 19, 1930 7 Sheets-Sheet 2 .24 g .247 53 .7! .JZ I 51 w .57 9 i 9 i .72 1 5% j 1 l 75 H .56 I j I) J5 J/ 5 Z5 1 42 w 1 Z5 47 Jan. 14, 1936. I c R ALDEN 2,027,360

FUEL INJECTION SYSTEM Filed March 19, 1930 7 Sheets-Sheet 3 GarmZZ 214M572 $4M, dub/W 1936. c. R. ALDEN ,02

' FUEL INJECTION SYSTEM Filed March 19, 1930 7 Sheets-Sheet 4 z? Gal /Lou y-CZJIM Jim. 14, 1936. c. R. ALDEN I I FUEL INJECTION SYSTEM Filed March 19, 1950 7 Sheets-Sheet 5 f'z ur zlr Carmll 1?. 7Z-

Jan. 14, 1936.

c. R. ALDEN FUEL INJECTION SYSTEM Filed March 19, 1930 7 Sheets-$11351} 6 0" 3.50" 77/15 lh PEG/F555 (7F CBQN/f' fil /AF T ROTATION Jan. 14, 1936. c. R'ALDEN 2,027,350

FUEL INJECTION SYSTEM Filed March 19, 1950 7 Sheets-Sheet 7 m 5% id Patented Jan. 14, 1936 UNITED ,STATES PATENT OFFICE 2,027,360 FUEL INJECTION SYSTEM Application March 19,

21 Claims.

The present invention relates to improvements in fuel injection systems for internal combustion engines.

Various objects of the invention reside in the provision of a novel fuel injection system in which fluid pressure actuated valves are employed instead of mechanically operated valves, thereby eliminating the springs, cams, cam followers and 'lost motion connections, commonly employed in prior systems; in which wear between coacting parts is substantially eliminated, thus obviating the necessity for adjustment and replacement of parts to compensate for wear; and in which there is a material reduction in the number, size, weight and cost of the coacting parts.

Other objects of the invention reside in a new and improved fuel injection system in which no high degree of precision'in the manufacture of the coacting parts is required for satisfactory operation, in which the initial cost is low, and in which maintenance involves little attention or expense.

Various general objects residein the provision of a novel fuel injection system which is practically noiseless in operation, which enables operation at unusually high speeds, which is highly responsive, certain and efficient in performance, and which is subject to a high degree of precision and sensitiveness in control.

Another object is to provide a new and improved fuel injection system comprising an injection valve adapted to be subjected at opposed ends to fluid pressure from a single source, and

distributor means for controlling the supply of fluid pressure in a manner such that in each sequence of operation like pressures first are impressed againstopposite ends of the valve, then the pressure at one end ismomentarily reduced to permit opening of the valve, and finally the pressure at the other end is reduced to permit closingof the valve.

A further object resides in the provision of such control means which is operable to effect only a partial reduction in the closing pressure, for example from 25% to 40% of the maximum, to induce opening of the valve, and which further is operable to reestablish the pressure before closing of the valve as a preparatory step'to insure quick and positive closing of the valve upon a reduction in the opposing pressure.

Another object is to provide a novel fuel injection system in which a single distributor or "control means is provided for a plurality of valves, in which said means is adjustable to effect a synchronous change in the occurrence or the du- 1930, Serial No. 437,056

(or. 12a-32) ration of injection for all valves, and in which said adjustment may be accomplished while theengine is in operation.

Still another object resides in the provision of a novel injection system having sets of distributor passages respectively, for supplying fuel to the discharge ends of a plurality of injection valves in timed sequence and for quickly exhausting the pressure after cut-off of the fuel supply, and for effecting pressure reduction impulses at the outer ends of the valves in timed sequence and also in timed relation to the supply of fuel.

Further objects and advantages will become apparent as the description proceeds.

In the accompanying drawings, Figure ,1 is a diagrammatic representation of a fuel injection system embodying the features of my invention.

Fig. 2 is an enlarged axial sectional view of one of the injection no'zzles.

Fig. 3 is a side elevational view of the nozzle.

Fig. 4 is a fragmentary plan view on an enlarged scale of the distributor and its tube connections. v

Fig. 5 is a transverse sectional view of the tube connecting block for the distributor taken along line 55 of Fig. 4.

Fig. 6 is a view similar to- Fig. 5 taken along line 6-6 of Fig. 4.

Fig. '7 is a sectional view taken along line ll-i of Fig. 5.

Fig. 8 is a. sectional view taken along line 9-3 of Fig. 6.

Fig. 9 is a sectional view taken along line 9-9 of 6- Fig. 10 is an enlarged the distributor.

Fig. 11 is a sectional view of the adjusting mechanism for the distributor taken along line H-|I of Fig. 10;

Figs. 12 to 17 are transverse" sectional views of the distributor taken respectively along lines "-42, Iii-I3, "-44, I5-I5, l6l6 and I1- 11 of Fig. 10.

Fig. 18 is a time chart showing the relation of the feed tube opening to the fuel source, the feed tube opening to the bleed, the period of pres-- sure reduction in the control tube, and hence the period of fuel injection, to degrees of crank shaft axial sectional view of rotation for all axial positions of adjustment of imposed on the development of the casing with the latter adjusted axially for closed throttle condition.

Fig. 20 is a view similar to Fig. 19 with the parts adjusted axially for idling throttle operation and showing the feed tube about to open to the fuel source.

Fig. 21 is a view similar to Fig. 20 showing the pressure reduction orifice about to open to the drain shortly before the cut-off of the feed tube to initiate fuel injection.

Fig. 22 is a view similar to Fig. 20 showing the parts in position to effect fuel injection.

Fig. 23 is a view similar to Fig. 20 showing the parts in position after the end of the fuel injection and with the feed tube vented to the pressure bleed.

Fig. 24 is a view similar to Fig. 19 with the parts adjusted axially for full open throttle operation, and showing the feed tube about to open to the fuel source.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the inventio to the specific form disclosed, but intend to c ver all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

The present system of fuel injection is adapted for use in various types of internal combustion engines. However, for purposes of illustration, I have shown in the drawings and will herein describe the system as applied to a Diesel englne for which it is particularly suitable.

The system comprises generally a plurality of injection nozzles, at least one for each engine cylinder, 9. source of fuel under a substantially constant pressure, and a control unit for the nozzles operable in timed relation to the rotation of the crank shaft and eflective through control of the nozzles to meter the respective charges of fuel and time the occurrence thereof in a given cycle.

Referring more particularly to the drawings, the specific fuel injection system, constituting the exemplary embodiment of the invention, is provided for a two-cycle Diesel engine having four cylinders of which only one is shown. Each cylinder comprises a cylinder body l0 open at one end and closed at the other end by a removable cylinder head II. A suitable piston I2 is slidably disposed in the cylinder I0, and is connected through a rod II to the engine crank shaft H. The piston I2 is so disposed in' the cylinder III that at the end 01' the compression stroke, a high degree of compression will be obtained in the initially small combustion space |5 underlying the cylinder head I Four fuel injection nozzles l5, l1, l8 and I9, one for each cylinder, are provided. Each nozzle is mounted to discharge a jet of fuel into the combustion space |5 over a predetermined controllable period of each cycle. Since the nozzles are alike in construction, a detailed description of the nozzle I will sumce for all.

Preferably, the nomle I5 is mounted'in the head (I to discharge centrally into the upper nozzle.

end of the combustion space l5. To this end, the head II is formedcentrally with a chamber 20 opening therethrough and adapted to house the The inner end of the chamber 25 is formed with a peripheral flange 2| which defines a central opening 22 and of which the outer surface is inclined toward the opening to define a conical seat 23 for the nozzle.

The nozzle IS in its preferred form (see Figs. 2 and 3) comprises an inner tip section 24 and an outer plug section 25. The inner end of the section 24 is conical in form to coact with the seat 23, and preferably has a central injection point 25 projecting through the opening 22 slightly into the combustion space IS. The outer end of the section 24 is formed with a central cylindrical boss 21, the outer peripheral edge of which seats against a beveled edge 29 in the inner end of the plug section 25. A plurality of screws ill extend through countersunk openings 3| in the tip section 24 into threaded engagement with the plug section 25 to secure the sections rigidly in assembled relation.

The plug section 25 projects beyond the head II, and the free outer end thereof is reduced in size to define an annular shoulder 32. A clamping plate 33 centrally apertured to receive the reduced end of the section 25 is tightly clamped against the shoulder- 32 by means of two screw bolts 34 at opposite ends threaded into the cylinder head II. Thus, the assembled nozzle I5 is clamped securely in the chamber 20 against the seat 23.

The tip section 24 is formed with an axial bore 35 opening through the boss 21 to the outer end. The inner end of the bore 25 is reduced in size to define a shoulder, the peripheral edge of which constitutes a valve seat 36. Opening from the reduced inner end of the bore 35 through the nozzle point 25 is a restricted fuel discharge orifice or duct 31 which preferably is branched laterally to discharge a plurality of fuel jets into the space l5. It is to be understood, however, that any suitable form of fuel jet adapted to satisfy requirements of combustion .spaces l5 of various shapes may be provided.

A valve plunger 38 is slidably mounted in the bore 35, and the inner end thereof is reduced in size to constitute the inner end of the bore or valve chamber 29. Formed on the inner end of the plunger 25 is a pointed or tapered valve 40 adapted to coact with the valve seat 35. A passage 4| formed in the tip section 24 opens to the side of the chamber 39, and is in free communication with the discharge end of a fuel feed tube 42 leading from a suitable source of fuel supply. Similar feed tubes 42, 44 and 45 are provided respectively for the nozzles l1, I8 and I5. Preferably, the feed tube 42 is threaded into the outer end of the tip section 24, ,and extends out of the chamber 25 through a longitudinal groove 45 formed in the side of the plug section 25.

The plug section 25 also is formed with an axial bore 41 which opens therethrough, and of which the inner end is enlarged to form a pressure chamber 45, and the outer end is tapped. The valve plunger 38 extends .into the chamber 45, and hence is responsive to the pressure therein. Preferably, the outer end of the plunger 25 is formed with a peripheral flange '49, and is encircled by a coil spring 55 in end abutting en-v adjustable upon removal of the cap screw 52 to 75 vary the maximum range of movement of the plunger. This adjustment can be'made while the engine is in operation and without necessitating any change in the other units of the system. The cap screw 52 servesto prevent leakage of fuel past the threads of the pin 5|.

Formed in the side of the plug section 25 is a recess 53, the inner end of which defines a conical seat and opens through a central connecting port 54 to the bore 41. A fitting having a conical inner end engaging the conical seat is snugly disposed in the recess 53, and is tightly clamped therein by means of a screw collar,55 in adjustable threaded engagement with a collar 56 encircling the plug section 25. The collar 55 is formed with an axial bore 51. The discharge end of a control tube 59 connected to a suitable source of pressure fluid extends through the bore 51, and is threaded into the fitting, and the irmer end of the latter is formed with a port 58 efiecting communication between the tube and the port 54. Similar tubes 60, 6| and 52 are provided respectively for the nozzles I'l, I8 and I9.

In the operation of the nozzle, the entire outer end area of the plunger'38 is always exposed to the pressure in the chamber 48. The inner end area is fully exposed to the pre sure in the chamber 39 when the valve 40 is o 11, but is reduced by the area embraced by the valve seat 36 when the valve is closed. Thus, assuming that equal pressures are impressed through the tubes 42 and 59, the valve 40 if closed will remain closed due to/the differential pressure acting on the. valve.

Upon a sufficient reduction in the pressure impressed through the tube 59, the valve 40 will open, thereupon immediately exposing the entire inner end area of the plunger to the pressure in the chamber 39. If now the pressure in the tube 59 is reestablished, the opposing pressures will be balanced, but the valve 40 will continue to remain open due to the pressure of the spring 50. However, upon reducing the pressure in the tube 42, the valve 40 will again close, thereby reestablishing the differential pressure relation tending to maintain the valve closed. The pressure of the spring 50 is weak relative to the fuel pressure acting on the differential area, which is equal to the area embraced by the valve seat, and hence will not be effective to open the valve.

Fuel is supplied through the tube 42 to the nozzle at a substantially constant pressure during injection. The metering of the charge thus is determined by the period of time that the n'ozzle is open. The start'of injection is coincident with reduction in pressure in the tube 59 below that in the tube 42. The end point of injection is coincident with the subsequent reduction in pressure in the tube 42 below that in the tube 59. Thus, the occurrence and metering of the charge are dependent on the control'of the pressures in the two tubes 42 and 59.

Fuel under a substantially constant pressure may be supplied to the feed tube 42 froin any suitable source. In the present instance, a suit able fuel pump, 63 driven by power from any suitable source (not shown) takes fuel through a'suction'line 64 from a fuel supply tank 65, and discharges the fuel at a high pressure through a line 66 to a fuel accumulator 61. The specific construction of the pump 63 per se forms no part of the present invention, and hence is not disclosed herein. The accumulator 61 is provided in the form of a' closed pressure container.

' Branching from the line 65 is a line 68 including a pressure relief valve discharging to the supply tank 65. The valve 69 is set to maintain a predetermined pressure, forexample 10,000 pounds per square inch, in the accumulator.

Opening from the accumulator 61 at a point below the liquid fuel level is a main high pressure feed line III which is adapted to be suitably connected in timed sequence during the successive periods of fuel injection through the nozzles to the respective feed tubes 42 to 45.

In the present instance, the discharge end of the line 'I0'is connected to one end of a bore II opening through a connection block 12. A pipe I3 in effect a continuation of the pipe I is connected at its inlet end to the other end of the bore II, and at its discharge end to a fluid distributor indicated generally at I4. Four feed lines I5, I6, 11 and 10 lead from thedistributor -'I4 and are connected through the block I2 to to 45 and I to 18 are respectively connected by means of suitable fittings. Interposed in the passages I9 to 82 are four valves 83, 84, 85 and 06 respectively whereby the supply of fuel to any nozzlemay be cut off.

Any suitable pressure fluid from any suitable source may be impressed through the tubes 59 to 52, Preferably, fuel from the accumulatortl is utilized. To this end, the block I2 is formed with four valve chambers 81, 88, 89 and 90 opening to the bore III, and also in communication with four chambers 9|, 92, 93 and 94. Suitable valves 95, 96, 9'1 and 98 control the passage of pressure fluid from the bore 'II into the chambers 91 to 90.

Orifice plugs 99,100, HM and I02 are. threaded into and close the chambers 9| to 94. Each plug is formed with an axial bore I03 and an intersecting transverse bore I04 opening at its ends to a peripheral groove I05 in the exterior. The inner ends of the bores I 03 in the respective plugs 99 to I02 are restricted to define orifices I06, I00,

I08 and. I09 opening to the chambers 9| to 94. Four transverse bores H0, III, 2 and H3 are formed in the block I2, and open to the chambers 9| to 94 into communication with the annular grooves I05. The inlet ends of the control lines 59 to 02 are connected respectively to the bores 0 to H3 by means of suitable fittings. Thus, the main feed line I0 is connected through four composite passages, valve controlled and including the restricted orifices I06to I09, to the individual control lines 59 to 52.

The distributor I4 constitutes means for controlling the pressures in the feed tubes and the control tubes to effect operation of the nozzles in timed relation to the rotation of the engine riod or duration of injection. While any suitable control means may be provided, in the present instance, the distributor is of the rotary type (see Fig. 10) comprising an outer cylindrical casing H4, and a rotor I|5 disposed therein for r0.- tary operation to effect timed sequential charges and for axial adjustment to vary the metering of the charges.

The inlet ends of the feed tubes'I5, I5, 11 and I8 open to the interior of the casing II 4 respectively, through equally spaced peripheral feed ports H5, H1, H9, and 9 formed therein.

Preferably, these ports are arranged in the same transverse plane (see Fig. 12). The main feed line 13 opens through the side of the casing II4 to a continuous peripheral groove I25 formed in the interior of the casing in a transverse plane adjacent the plane of the feed ports II6 to H9 (see Fig. 13).

Formed in the periphery of the rotor H5 is a longitudinally inclined recess I 2I which is always in communication with the groove I20, and which is ell'ective upon rotation of the rotor to establish successive communication of the groove I with the feed ports II6 to H9. It will be evident that upon axial adjustment of the rotor I I5, the opening and the cut-off of the feed ports II 6 to H9 will be advanced or retarded relative to the rotation of the crank shaft I4. The duration of any one period of injection at each nozzle is determined by the interval between the instant of pressure reduction in the related control tube and the variable instant of cut-01f of the related feed tube. In the present illustration, the duration of injection varies'from maximum to zero as the rotor I I5 is adjusted downwardly.

Thus, when the upper end of the inclined recess I2I is adjusted into the plane of the ports IIG to H9 for movement into successive communication therewith, the duration of injection is short and but a small amount of fuel is injected. Under such condition, which exists during idling operation, it is desirable to dissipate the pressure in each feed tube immediately after it is out 011 from the fuel supply.

Hence, a second recess I22, which is parallel to and spaced rearwardly of the recess I2I, and

- which slightly overlaps the upper end of the latter is formed in the rotor H5. The recesses I 2| and I22 are spaced apart just sumciently to prevent any one of the ports II6 to H9 from being in communication with both simultaneously. The bleeder recess I22 may be vented to any suitable exhaust, and in the present instance opens to the upper end of the rotor II5. For convenience, the ports'II6 to H5 and the recesses HI and I22 are therefore located near the upper end of the distributor 14. The upper end of the easing II4 which is closed by a removable cover I23 opens through a suitable line I24 to the exhaust.

The distributor 14 is also utilized as a means to bleed pressure fluid from the control tubes 59 to 62, in sequence and during intervals timed to the rotation of the crank shaft I4, at"a rate faster than the supply of pressure fluid through the respective orifices I06 to I09 so as to effect successive pressure reductions in the control tubes.

To this end, by-pass tubes I25, I25, I21 and I28 are connected at their inlet ends to the bores I I 0 to H3 in the block 12, and thus are always in communication with the control tubes 59 to 62. The tubes I25 to I28 open to the interior of the casing II4 respectively through equally spaced peripheral ports I29, I30, I3I and I32 formed therein. Preferably, these ports are arranged in the same transverse plane (see Fig. 14). Formed in the inner periphery of the casing H4 in a transverse plane spaced from that of the ports I29 to I32 is a drain port I33 (see Fig. 16) which is connected to a drain-line I34 discharging to the supply tank 65.

A plurality of equally spaced longitudinal recesses I35, I36, I31 and I are formed in the periphery of the rotor H5. and are in intercomrnunication through a branched duct or passage I33 (see Fig. 15) formed in the rotor. The

recesses I35 to I38 are in the same transverse plane, and are of such a length and so located longitudinally of the rotor that upon rotation of the latter in any position of axial adjustment, they will be moved successively into and out of communication with the drain port I33.

One of the recesses I35 to I39 for example the recess I35, is extended in length at one end to project through the plane of the control ports I29 to I32, and is adapted upon rotation of the rotor H5 in any position of axial adjustment to be moved successively into and out of communication with the control ports. It will be evident that when the recess I35 is open to one of the control ports I29 to I32, and one of the recesses I36 to I38 is open to the drain port I33, the control port in question will be vented to the drain and a drop in ,pressure in the connected control tube will result.

Preferably, means is provided for preventing a pressure drop to zero or a pressure drop substantially greater than necessary for the efllcient operation of the system in the control tubes 59 to 62 upon selective venting to the drain. To this end, a suitable pressure restriction means, such for example as a pressure reducing orifice I40, is interposed in the drain line I34. The orifice I40 preferably is larger than any one of the orifices I06 to I09, but not necessarily so. When pressure fluid is allowed to escape through the orifice I40, fluid will flow through one of the orifices I06 to I09 at that particular time in series therewith, and this flow will result in a drop in the control tube pressure. Sub-dividing the pressure results in that after the drain cut-off, the maximum control pressure can be quickly established, thus providing a. sensitive and highly responsive control permitting extremely high engine speeds.

The casing H4 is removably secured on a cylindrical housing I U in turn removably secured to a suitable support I42, and one end of the rotor I I5 extends from the casing through the housing and the support for a suitable drive connection with the crank shaft I 4. This connection is shown as comprising a spiral gear I43 slidably splined to the rotor I I5 and meshing with a spiral gear I44. The latter also meshes with a spiral gear I45 driven by the crank shaft I4.

A sleeve I46 within the housing I is secured on the rotor II5 for relative rotation. Two collars I41 rigidly clamped to the rotor H5 in end abutting engagement with the sleeve I46 serve to hold the latter against relative endwise movement. The sleeve I46 is splined to the housing I for axial movement with the rotor I I5, and is formed along one side with a longitudinal gear rack I40.

A gear sector I49 secured to a shaft I50 journalled in a bracket I5I on the outside of the housing I H extends through a longitudinal slot I52 in the latter into mesh with the gear rack I48. Any suitable means, either manual or governor actuated, may be provided for adjusting the sector I49 to adjust the rotor II5 axially. Herein. I

have shown a manual means comprising an arm.

I53 secured to the shaft I50 and pivotally connected at its free end to one end of a link I54. The other end of the'link I 54 is pivotally connected to a control lever I55 pivotal on a stud I55 projecting through a suitable support I51. Preferably, a suitable ratchet sector I58 is rigidly secured on the stud I56 at one side of the support I51, and the lever I55 is provided with a manually releasable spring-pressed detent I58 for engaging said sector to maintain the rotor III in axial position of adjustment.

Thus, the rotor H5 may be adjusted axially to vary the occurrence of the opening of the feed tubes-42 to 45 to the fuel source relative to the crank shaft movement. The angular phase relation between the venting of the control tubes 59 to 62 to the exhaust and the rotation of the crank shaft I4 is unaffected by this adjustment, and may be constant over the entire range'of engine operation from closed throttle condition to full load condition.

The angular phase relation between the crank shaft I4 and, the rotor II5, however, may be adjusted when desired by adjusting the spiral gear I43 axially relative to the gear I44, move-.

ment in one direction (upwardly) serving to retard the point of injection, and movement in the opposite direction (downwardly) serving to advance the point of injection. The gear I43 has a hub I60 formed with a peripheral groove I6I in which a ring- I62 is rotatably disposed. A yoke I63 pivotally engages trunnions I64 on the ring I62, and is formed on one arm of a bellcrank lever I65 pivotal on a stud I66. The other arm of the lever I65 is connected through a link I61 to one end of a control lever I68 pivoted intermediate its ends on the stud I56. The other end of the lever I68 constitutes a handle having a manually releasable spring pressed detent N59 for engaging a ratchet sector I mounted on the support I51 to hold the gear I43 in position of adjustment.

The operation will no ence to Figs. 18 to 24.

Fig. 18 is a time chart in which the degrees of throttle opening, i. e. the axial adjustment of the rotor I I5 from closed throttle to full open throttle, are plotted along the ordinate, and in which the be described by referdegrees of crank shaft rotation including any period of fuel injection are plotted along the abscissa. The. area 'a--bc-.-d represents the recess I2I, the feed tube opening to the fuel source along line a)d, the feed tube cut-oh? occurring along line b-c, and any abscissa between said lines indicating the duration of feed tube opening in degrees of crank shaft rotation.

" The area e-,f-g-h represents the recess I22,

the feed tube opening to this recess along the 7 line e-h and moving out of communication therewith along line f-g.

The area i--a'-k-Z represents the period of pressure reduction in the control tube, the pressure being reduced along line z'-l and being reestablished along line 7'k. It will be understood that'the invention is not limited to the specific .relation'of these areas to the degrees of crank shaft rotation. The phase relation is subject to adjustment through manipulation of the lever I68 so as to effect fuel injection at any desired point in the piston cycle.

- In Fig.v 19, the rotor [I5 is shown adjusted axially into its lowermost position beyond closed throttle condition. Assuming movement of the rotor H5 in the direction of the arrow (Fig. 19), the recess I2I will move into communication with the port H6 at a (311) thereby connecting the feed tube 42 to the fuel source. The valve.40,

however, will not open since the differential area, which is equal to the area embraced by the valve seat36, is acted on by the pressure in the control tube 59, the pressures at this time in the tubes 42 and 59 being equal. Subsequently, the elongated recess; I35 will open to the port.I29. However, the pressure in the .control tube 59 -will not-'be reduced since the port I33 is still closed. At b (356) the port II6 will be closed at m (318).

thereby cutting off the feed tube 42 from the fuel source, but trapping fuel therein at the pres sure of the fuel source. The period during which the feed tube 42 is open is represented by the line 0-1). Thereafter, at e (358) the recess I22 will open to the port I I6 thereby causing the trapped pressure to be dissipated.

At 1 (upper dead center0) the recess I36 will open to the drain port I33, and since the recess I35,,which is connected to the port I33 through the passage I39 is still open to the port I29, pressure fluid will bleed from the control tube 59. The pressure fluid will bleed past the orifice I40 more rapidly than. pressure fluid from the full source can pass-through the orifice I06, and hence a pressure reduction will occur in the tube 59. However, since the fuel pressure is not impressed through the line 42 at this time, the valve 40 will remain closed. Subsequently, at 9' (10) the port I29'w'ill be closed, thereby causing the original pressure in the tube 59 to be reestablished. At f (26), the recess I22 will move out of communication with the port H6. The operation is the same for each of the other nozzles I1, I8

and I9 excepting for successive phase diiferences Figs. 20 to 23 show the corresponding sequence for idling throttle. Upon movement of the rotor H5 in the direction of the arrow, the recess I2I will open to the port II6 (see Figs. 18 and 20) At 12 (0), the recess I38 will open to the port I33 (see Fig. 21), thereby resulting in a pressure reduction in the control tube 59 suflicient to overcome the differential pressure initially acting to keep the valve 40 closed. Thereupon, the fuel pressure in the tube 42 will raise the valve to inject fuel into the cylinder I0 (see Fig. 22).

' The port II 6 will be closed at 0 (2) to cut-ofi the supply of fuel to the nozzle. The pressure in the tube 42 will rapidly: fall to a point below the reduced pressure in the tube 59 to effect'closure of the valve 40. At 9 (5), the recess I22 will open to the port II6 thereby venting the pressure in the tube 42 (see Fig. 23) to insure positive closing or the valve 40. It will be evident that fuel is injected only over a very small period of time, i, e. along the line 10-0. duration that the valve 40 is returned to its seat 36 before it has had time to reach its uppermost limit of movement defined by the adjustable pin 5|. The recess I35 moves out of. communication with the port I29 at q (10) to reestablish the pressure in the tube 59, and the recess I22 leaves the port H6 at r (33") to disconnect the tube 42 from the bleed.

The action is of such short- Fig. 24 shows the corresponding sequence for full throttle. In this instance, the recess I2I will open to the port H6 at d (354) and the recess I 36 will open to the drain port I33 at 1 (0).

Thereupon, the valve 40 will open and injection I will commence.

The recess I35 will leave the port I29 at k (10) to reestablish the pressure in the control tube 59. However, the valve 40 will not close at this time since the pressure at the opposite ends of the valve plunger 38 and the areas against which they act are equal, and the spring 50 thus is effective to hold the valve from floating into closed position.

The recess I2I will leave the port I I6 at c (38) thereby cutting 01! the supply of fuel to the tube 42. Since the pressure in the tube 59 has been reestablished, the valve 40 will close quickly. It will be evident that fuel is injected over a relatively long period of time, i. e.

along the line lc. In full throttle adjustment, the recess I22 does not project through the plane of the ports Hi to III, and hence is not brought into communication therewith.

In general, it will be evident in the operation of the nomle "that pressure reduction in the tube and hence the injection period is initiated upon opening of the recess I30 to the port I33, that pressure restoration is initiated upon movement of the recess I" from the port I29, and that the injection period is terminated upon movement of the recess ill from the port H6. While I have disclosed one specific arrangement of ports and recesses and have described the operation for one phase adjustment, it is to be understood that the invention is intended to cover any arrangement which will efi'ect opening and closing of the injection or metering valve through variation in the pressure impulses acting thereon, and over any suitable phase of the crank shaft rotation.

Thus, the plunger H5 is adjustable axially to vary the duration of injection, the starting point of injection remaining fixed. Since the fuel is supplied from a constant high pressure source. the fuel charge is metered very accurately. The phase relation of the starting point of injection to the crank shaft rotation is also susceptible of adjustment. Both adjustments of the plunger H5 may be effected during operation of the engine. Since a single control for all of the nozzles is provided, the adjustments for the nozzles are always synchronized.

The pressure drop in the control tubes 59 to 82 is limited, and preferably is from 25% in 40% of the maximum, or just sufiicient to insure opening of the injection valves at the desired times. Any desired extent of pressure drop can be obtained. The pressure drop is also of short duration, and under most operating conditions the initial pressure is reestablished before the end of injection preparatory to closing the respective valves. As a result, the valves are closed quickly and positively. The momentum of the fluid in the control tubes prevents rebounding or reopening of the valves, and hence prevents dribbling after injection. The pins 5| serve to limit the travel of the valves ll. Adjustment of the extent of travel of any one valve 38 through adjustment of the corresponding pin I slightly varies the volume of fuel injected past said valve without influencing the volume of fuel injected past any of the other valves. Hence the pins 5i serve as a means for compensating for variations in the respective valves, such for example as variation in the diameters of the orifices 31, likely to result in practice due to manufacturing tolermm. The adjustments of the pins 5| may be ei'fected while the engine is in operation.

The-effect of leakage past any part subject to pressure differences is greatly minimized. Any leakage that might occur in the nozzles or in the distributor would not affect the amount of fuel injected.

In general, it will be evident that I have provided a highly advantageous fuel injection system which is eiiicient in operation and can be operated at unusually high speeds, and which is subject to an accurate and sensitive control. The construction is simple and inexpensive, and obviates many of the objections such as noise, wear, imperfect timing and metering, lack of synchronism, etc., inherent in many prior systerns.

While I have herein shown the invention applied to a fuel injection system in which the fuel is injected under its own pressure, it is to be understood that the invention in its broad aspects is applicable generally to a fuel or fiuid metering system. Such a metering system might be used for supplying fuel to an injection nozzle in which the actual injection is accomplished by separate means, such as an air blast, or for supplying fuel to engines operating on the Otto cycle, or for metering and distributing lubricating oils and pating the fluid pressure at one end of said valve' member while maintaining the pressure at the other end of said valve member to effect movement of the latter from one position to the other.

2. A fuel injection system, comprising, in combination, a source of liquid fuel under pressure, an injection nozzle having a fluid pressure responsive valve member, and a rotary distributor for effecting the simultaneous supply of fuel from said source at equal pressures to opposed pressure areas on'said member and for dissipating the pressure on one of said areas after a predetermined interval while substantially maintaining the pressure on the other of said areas to cause movement of said member from one position to another.

3. A fuel injection system comprising, in combination, a source of fuel under a constant pressure, an injection nomle having a valve member with opposed pressure areas and having a discharge orifice opening from one of said areas, and means for directing fuel from said source at equal pressures simultaneously to said areas and for reducing after a predetermined interval the pressure on one of said areas while substantially maintaining the pressure on the other of said areas to effect movement of said valve member by the pressure acting on the other of said areas.

4. A fuel injection system comprising, in-combination, a valve casing having an injection outlet, a reciprocable valve member having a lifting pressure face adapted to seat over said outlet and having an opposed seating pressure face. a passage opening constantly to said opposed pressure face, means constantly open to said passage for supplying fiuid under pressure thereto, means for periodically directing fuel under pressure to said first mentioned face, and means operable over a predetermined period during the application of pressure to said first mentioned face to reduce the pressure acting on said opposed face below that acting on said lifting face to permit movement of said valve member into open position.

5. A fuel injection system comprising, i bination, a valve casing having an injection tlet, a reciprocable valve member having a pressure valve face providing a valve for said outlet and having an opposed pressure face, said faces being substantially equal 'in area, the effective area of said valve face being reduced by the area of said outlet when thelatter is closed. a passag e opening constantly to said opposed face, means constantly open to said passage for supplying fiuid under pressure thereto, means for directing fuel under a pressure substantially equal to said fluid pressure to said valve face, and means for temporarily partially dissipating the pressure acting on said opposed face to effect opening of said outlet.

6. A fuel metering system comprising, in combination, a valve casing having a discharge duct, a reciprocable valve member having a pressure valve face adapted to open and close said duct and having an opposed pressure face, said faces being substantially equal in area, a source offuel under a constant pressure, means for supplying fuel from said source to said opposed face, means for supplying fuel from said source to said valve face, and means for reducing the pressure on said opposed face while said last mentioned means is operative to effect movement of said valve memher away from said duct into open position.

'7. A fuel injection system comprising, in combination, a valve casing having a discharge duct, a reciprocable valve member having a pressure valve face adapted to open and close said duct and having an opposed pressure face, said faces being substantially equal in area, a source of fuel under a constant pressure, means for supplying fuel from said sourceto said opposed face, means for simultaneously supplying fuel from said source to said valve face, means for first reducing the pressure on said opposed face to effect movement of said valve member away from said duct into open position, and then for reestablishing the initial pressure on said opposed face, and spring means acting on said valve member to hold the latter in open position after the reestablishment of the pressure on said opposed face.

8. A fuel injection system comprising, in combination, a valve casing having a discharge duct, a valve member reversibly movable to open and close said duct, said member having two opposed pressure faces, means including a flow restricting orifice continuously in communication with one of said faces for feeding fluid under pressure thereto, means operable at timed intervals to supply fuel under pressure to the other of said faces, and means operable in timed relation to said last mentioned means to divert fluid under pressure from said first mentioned means at a point between said one valve face and said orifice.

9. 'A fuel injection system comprising, in combination, a valve casing having a discharge duct, a valve member reversibly movable to open and close said duct, said member having two opposed pressure faces, a source of fuel under pressure,- means including a flow restripting orifice for feeding fuel from said source through said orifice to one of said faces, means operable at timed intervals over a fixed period to supply fuel from said source to the other of said faces, and means operable in timed relation to said last mentioned means during each period to divert from said first mentioned face fuel feeding past said orifice,

said second mentioned means being adjustable relative to said last mentioned means to vary said relation.

' 10. A fuel injection system comprising, in combination, a valve casing having a discharge duct,

a valve member reversibly movable to open and close said duct,said member having two opposed pressure'faces, means including a flow restricting orifice continuously in communication with one face for feeding fiuid under pressure thereto, means operable at timed intervals to supply fuel under pressure to the other face, and means including a flow restricting orifice larger than said first mentioned orifice and operable in timed relation to 'said last mentioned means to bleed fluid pressure feeding past said first mentioned orifice from said first mentioned means to effect a pressure reduction at said one face.

11. A fuel injection system comprising, in combination, a valve casing having a discharge duct, -a valve member reversibly movable to open and close said duct, said member having two opposed pressure fa'ces, means including a flow restricting orifice for feeding fluid under pressure to one of said faces, means operable over a. fixed interval to supply fuel under pressure to the other of said faces, and by-pass means branching from said first mentioned means between said orifice and said one face and including a flow orifice and valve means operable at a predetermined point Within said interval to open said bypass means to bleed fluid under pressure from said first mentioned means through said last mentioned orifice.

12. A fuel injection system comprising, in com bination, a valve casing having an injection outlet, a reciprocable valve member in said casing,

said valve member having a pressure valve face adapted to coact with said outlet and having an opposed pressure face, a source of fuel under pressure, and means for directing fuel from said source to said casing against said faces to effect in sequence the application of equal pressures on said faces, a reduction in pressure on said 0pposed face permitting-opening of said outlet, and a cut-off of pressure on said valve face permitting closing of said outlet.

13. A fuel injection system comprising, in combination, a valve casing having an injection. out- I let, a reciprocable valve member in said casing,

said valve member having a pressure valve face adapted to coact with said outlet and having an opposed pressure face, a source of fuel under pressure, and means for directing fuel from said source to said faces to effect in sequence the simultaneous application of full pressure on each of said faces, a reduction in pressure on said opposed face permitting opening of said outlet, a reestablishment of the full pressure on said opposed face, and a reduction in pressure on said valve face permitting closing of sa d outlet.

14. A fuel injection system comprising, in combination, a valve casing having an injection outlet, a reciprocable valve member in said casing, said valve member having a pressure valve face adapted to coact with said outlet and having an opposed pressure face, a source of fuel under pressure, and means for directing fuel from said source to said valve member to effect in timed sequence the application of equal pressures to said faces, a reduction in the pressure-0n said opposed face, and a cut-off of the fuel under pressure acting on said valve face, said means being adjustable to varythe point of cut-off relative to the point of pressure reduction.

15. A fuel injection system comprising, in combination, a plurality of valve casings, each having an injection outlet, a plurality of fluid pressure responsive valve members, one reciprocable in each casing and controlling the opening through the allotted outlet, a source of fuel under pressure, a plurality of control lines connecting said source respectively to said casing for directing fuel against one face of each valve member, a plurality of by-pass lines one from each control line, a plurality of feed-lines for directing fuel respectively to said casing against the other face of each valve member, and rotary means for connecting said feed lines in timed sequence to said source and for venting said by-pass lines in a similarly timed sequence to a relatively low pressure, with the connection of the feed line and the venting of the by-pass line for each casing being concurrent over a predetermined period, said rotary means being adjustable to vary said period.

16. A fuel injection system comprising, in combination, a valve casing having an injection outlet, a fluid pressure responsive valve member movable in opposite directions to open and close said outlet, said valve member having opposed pressure faces, means for supplying fluid under pressure to one of said faces, means for supplying fuel under pressure to the other of said faces and to said outlet at predetermined intervals, a by-pass line opening from said first mentioned means, said by-pass .line including a restricted drain orifice, and valve means for opening and closing said line, said valve means being timed with respect to said second mentioned means to open said by-pass line during the supply of fuel to said other pressure face and thereby to effect a pressure reduction in said first mentioned means causing opening of said valve member.

1'7. A fuel injection system for an internal combustion engine with a crank shaft, said system comprising, in combination, a plurality of injection nozzles, each nozzle comprising a casing with an injection outlet and a reciprocable valve mem-- ber with inner and outer pressure faces, each inner face controlling the allotted outlet, a source of fuel under pressure, a plurality of control tubes for directly connecting said source respectively to said casings to direct fuel against said outer faces, individual adjustable valve means in said control tubes, a plurality of feed tubes for sup-' plying fuel to said casings against said inner faces, and a rotary distributor operable from said crank shaft for connecting said feed tubes in timed sequence to said source and for venting the pressure from said control tubes in timed sequence over an interval concurrent with the supply of the latterinto open position and after a prede- 19. A fuel injection system comprising, in combination, a source of fuel under pressure, an injection nozzle having a reversibly movable valve member with opposed pressure areas and having a discharge orifice opening from one of said areas, a and power means operable to effect the application of fuel from said source at a predetermined high pressure to the other of said areas and periodically to simultaneously establish an uninterrupted passage for the flow of fuel between said 10 source and said one area, and then operable to relieve the pressure acting on said other area while maintaining said passage so as to lift said valve member and supply fuel to said orifice.

20. A fuel injection system comprising, in com- 16 bination, a valve casing having a discharge oriflce, a reciprocable valve member having a pressure valve face adapted to open and close said orifice and having an opposed pressure face, said faces being substantially equal in area, a source 20 of fuel under pressure, means for supplying fuel from said source to said opposed face, means for simultaneously supplying fuel from said source to said valve face, and means for first reducing the pressure on said opposed face to effect movement of said valve member away from said orifice into open position, and then re-establishing the initial pressure on said opposed face, said second mentioned means being operable to reduce the pressure on said valve face after said re-establishment 80 of pressure on said opposed face to effect movement of said valve member into position to close said orifice.

21. In a fuel injection system, in combination,

a plurality of fluid pressure operable valves, each 86 valve having a reciprocable valve member with lifting and seating areas respectively at opposite ends, a plurality of feed tubes having inlet feed ports and opening respectively to said valves in communication with said lifting areas, a plurality of control tubes having control ports and opening respectively to said valves in communication with said seating areas, a source of fuel under pressure, rotary distributor valve passages for connecting said source sequentially over predetermined pel'iods through said feed ports to said respective feed tubes, means for supplying fluid under pressure to said control. tubes and including rotary distributor valve passages cooperating with said control ports for effecting pressure fluctuations in i0 timed sequence in said respective control tubes and in overlapping relation to said periods of fuel supply to said feed tubes to eflect opening and closing of said valves, and means for rotating said first and second mentioned passages in unison l5 relatively to said feed and control ports respecively.

CARROLL R. ALDEN. 

